NONDESTRUCTIVE CHARACTERIZATION OF SEMICONDUCTOR MULTILAYERS

This article reviews the use of spectroscopic ellipsometry (SE) for determining layer thicknesses, compositions, and surface and interface roughness of complex multilayer structures. An indirect technique, SE relies on an accurate database of dielectric functions techniques. Examples shown here use recent data on strained and relaxed Si1-xGex strained and relaxed InxGa1-xAs, and unstrained InxAl1-xAs, obtained from single epilayers, to and analyze SE data from both lattice-matched and pseudomorphic multilayer structures. The SE method has great potential form-line and in-situ use, leading ultimately to real-time process control.